Problem Valve Spring!
340's use the same rocker arms as a 318. You just need to clearance them as they did for all 340's. Looka at the pictuere from the Direct connection engine book. The arrow shows were they are ground. Even newer expensive rockers need to be clearanced. With a fixture, Index table, and a mill, There is no guessing. I would have yours clearanced at a local machine shop. First picture shows a line where the spring rubbed. The last picture shows what had to be removed.
340's use the same rocker arms as a 318. You just need to clearance them as they did for all 340's. Looka at the pictuere from the Direct connection engine book. The arrow shows were they are ground. Even newer expensive rockers need to be clearanced. With a fixture, Index table, and a mill, There is no guessing. I would have yours clearanced at a local machine shop. First picture shows a line where the spring rubbed. The last picture shows what had to be removed.
